Indicating device for fluid tanks



Nov. 17, 1925.

I L. DE FOREST INDICATING DEVICE FOR FLUID TANKS- Filed June 13. 1919 QUQMW Patented Nov. 17, 1925.

. UNlTE-D STATES PATENT OFFICE.

LEE DE FOREST, OF NEW YORK, N. Y.

INDICATING DEVICE FOR FLUID TANKS.

Application filed June 13, 1919. Serial No. 304,034.

'To all whom it may concern:

Be it known that 1, LEE on FOREST, a citizen of the United States, residing at New York, county and State of New York, have made a certain new and useful Invention in Indicating Devices for Fluid Tanks, of which the-following is a specification.

This invention relates to'indicat'ing devices for fluid tanks.

' The object of the invention is to provide a device for indicating when a fluid contained in a tank is nearly completely drawn Oil or the tank'has become empty.

.A further object of the invention is to provide an indicating device particularly for use in connection with gasoline tanks for automobiles or the like which will give an audible signal when the gasoline has been nearly consumed.

Further objects ofthe invention will appear more fully hereinafter.

The invention consists substantially in the construction, combination, location and relative arrangement of parts, all as will bemore fully hereinafter set forth, as shown by the accompanying drawing, and finally pointed out in the appended claims.

Referring to the drawing: Fig. 1 is a sectional view of a gasoline tank equipped with an audible signal device embodying my invention.

Fig. 2 is a similar view ofa slightly modified construction.

The same part is designated by the same character wherever it occurs throughout the several views.

While I have shown and will now describe my invention as applied to a gasoline tank particularly adaptable for useon automobiles or other motor vehicles, I Wish it to be understood that the principle thereof is a pplicable for use in all arts Where it is desired to obtain a signal when a fluid contained in a tank or container is nearly ex hausted therefrom. It is among the special purposes of my invention to provide an audible signal which. becomes operative when the gasoline in the tank iswithdrawn below a predetermined point therein. Referring to Fig. 1 as illustrative of the principle of my invention, the tank is indicated at 1, in the bottom of which, and preferably in place of the :usual drain cook or plug, I insert the end 2 of a. tube, preferably fleaible. Into the end of the t he 10 which is 2 is inserted a small straight metal tube 4 extending practically the entire height ofthe tank 1. In the top of the tube 4 are a plurality of small holes or slits 3. Slidably mounted over' the tube 4 is a sleeve 5 which 1s supported by means of arms 6 secured to the end of a float 7, likewise slidahly mounted around the tube 4. The float may he of any suitable material such as cork, balsa wood or the like, and is large enough in volume to lift the sleeve valve 5 upwards on the tube 4 to completely cover the holesor slits 3 in the tube when the fluid within the tank is sufficient in quantity to rise above the level of the float. The float 7.1s not larger in diameter than the plug 2 which enables the assembled device illustrated in Fig. 1 to be inserted inthe tank through the opening in which is seated the plug 2. The tube 4 is in communication as above explained, with the tube 10, Wl11Cll, as above stated, may be either flexible or metal, such as copper, which tube 10 extends under the bottom of the car to the posit on where it is desired to locate the sig nalhng device. The end of the tube 10 has mounted thereon an ordinary air whistle 11 comprlsing a sealed cap with a small perforation or hole 12 therein. If desired a cutofl' valve or cock,13 is inserted-in thetube 10 at a point easy to be reached by the driver to shut oil the noise of the whistle if it becomes annoying and after it has sounded its warning. The operation of the device s as follows: As long as the gas in the tank lsahove a certain minimum amount, i. e., above the level of the float 7 it holds the float 7 up as far as the flange 14; at the end of the tube a will permit the sleeve 5 to go, thus covering the perforations 3 inthe tube 4. When the gas gets below this minimum level, however, or the danger level,say three gallons 111 the tank are left, then the float having dropped with the fluid and the sleeve valve dropping with it uncovers the holes 3 in the pipe 4:- Since the air intake into the tank via the tube 10 and the whistle 12 is of considerably greater area than the usual pm hole in the cap or the tank air will be drawn into the tank through the whistle l2 and make a shrill, piercing but not loud sound which will warn the driver that he is on his last measure at asoline or, in the illustration above, on his last two or three gallons. In Fig. 2 I show a slightly modified construction tor actuating this ainilihle arrangement I provide the usual hole 16 in the cap 15. So long as the gas, level is above the lower end of the tube l the air coming into the tank must enter as usual through the hole 16 which leads into a tube 17. This tube is closed at the lower or flanged end and is provided with holes or perforations 18 near said end. 5 in this instance which is slidably mounted on the tube 17 is connected by rod 19 to the float 7 which is slidably mounted on the tube l. The flange 14 at the extreme end of the tube, 17 limits the downward move-' ment of the sleeve 5 so that when the float 7 drops with the fluid contained in the tank 1 the sleeve 5 will cover the holes 18 in the tube 17. As long as the gas level is above the float 7 the air coming into the tube must enter as above stated through the hole 16, but when the float drops the air inlet into the tank 1 is solely through the whistle 11 and tube 4, as the valve 5 covers the hole 18 in tube 17, and hence the whistle will blow; lt is of course apparent that the sleeve 5 is controlled in its movements by the float 7 which in turn is controlled by the amount of fluid in the tank.

If desired, air inlets 3' may be provided in tube 4 near the lower end thereof to be covered and uncovered by float 7 in accordance with the level of the liquid and thereby cause the whistle to be operated or not.

It is obvious that the float 7 and the sleeve 5 may be dispensed with in the arrangement here shown inasmuch as the difference in the diameter of the respective tubes 17 and 4 render it unnecessary to close the small openings 18 in the tube 17' after the bottom of the tube 4 has been'uncovcrcd as this tube being of larger diameter than. the tube 17 the air will rush in more readily through the tube 4 than through the tube 17 and thus actuate the whistle after the lower end of the tube 4 has been uncovered.

I have shown the whistle 11 as on the outside of the cap 15 but I do not wish to be limited or restricted inthe particular location of the whistle, or the direction of the air therethrough. I have shown also a feed supply pipe 20 through which the liquid from the tank is caused to flow and thereby operate the whistle when the set liquid level is reached.

Many other changes in details will readily The sleeve rea ses,

occur to those skilled in the art without dcparting from the spirit and scope of my 1nvention as defined in the claims, and therefore having set forth the objects and nature of my invention, and having shown and described specific structures embodying theprinciples thereof, what I claim as new and useful and of my own invention and desire to secure by Letters Patent is,-. a

1. The combination with a fluid tank, having a normally open air inlet thereto of restricted size, and a normally closed air inlet of comparatively larger size, a signalling device associated with said last mentioned inlet to be actuated by air passing therethrough, and means for opening said lastinentioned inlet when the liuid in said tank has dropped below a predetermined point, and means actuated thereby for closing said first mentioned inlet.

2. The. combination with a fluid tank, having a normally open air inlet thereto of restricted size and a normally closed air inlet of comparatively larger size, an audible signal device located in said last mentioned inlet to be actuated by air passing there through, and means for opening said last mentioned inlet when the fluid in said tank has dropped below a predetermined point, and means actuated thereby for closing'said lirst mentioned inlet.

3. The combination with a fluid tank, having a normally opcn air inlet thereto of restricted size and a normally closed air inlet of comparatively larger size, an air whistle located in said last mentioned inlet and actuated by air passing therethrough, and meansl'or opening said last mentionedinlet when the fluid in said tank has dropped below a predetermined level, and means actuated thereby for closing said first mentioned inlet.

l. The combination with a fluid tank, of

an air tube extended within said tank, a whistle located on said tube to be actuated by air passing thercthrough, and slidable means on said tube for causing said whistle tobecome operative.

5. Tho-combination with a fluid tank, and a removable cap therefor, of a hollow tube carried by said cap, and extending therethrough, said tube being of such length that when said cap is in normal position relative to the tank, the end of the tube within the tank is out of contact therewith, a whistle associated with said tube to be actuated by air passing therethrough, and slidable means on said tube Within the tank for causing said when said cap is in normalposition relative to the tank, the end of thetube' within the tank is out of contact with the bottom thereof, and a whistle located insaid tube to-be a removablecap therefor, of a holl ow tube carried by said cap, through,

and extending theresaid tube being of such length that when said cap is in normal position relative to the tank, the end of the tube within the tankis out of contact with the bottom thereof, and a whistle located in said tube to be actuated by air passing therethrough, a float slidably mounted on said tube, an auxiliary air inlet, a valve for closing said auxiliary in1et,--'and.a connection between said valve and float for obtaining simultaneous movement thereof.- i In testimony whereof I have hereunto set my hand on this 31st day of May, A. D.

' LEE DE FOREST. 

